Security document with a security component and method for the production thereof

ABSTRACT

The invention relates to a security document with a security element having at least a first layer with gaps in the form of characters or patterns or the like, and a discontinuous magnetic layer in the form of a coding disposed below said first layer. In the areas where the gaps and the magnetic layer overlap, the gaps are also present in the magnetic layer. The invention further relates to a security element and to methods for producing said element and the document.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a security document with a security elementhaving at least a first layer with gaps in the form of characters orpatterns, and a magnetic layer disposed below said first layer. Theinvention relates further to such a security element and to methods forproducing said element and the document.

2. Discussion of Related Technology

It has been known for some time to provide security documents withplastic security threads having a magnetic coating and thus serving as amachine-readable security feature (DE 16 96 245 A1, EP 0 310 707 A1).

To increase the forgery-proofness of this proven security featurefurther, it has also been proposed to provide the magnetic coating onthe carrier material in discontinuous form. For example EP 0 407 550 A1describes a security document with an embedded security thread providedwith a binary code consisting of magnetic material. Certain bit lengthsare defined which are constant over the total length of the strip. Thecoating of a bit length with magnetic material corresponds for exampleto a 1 while a bit length without magnetic material corresponds to a 0.The binary code known from EP 0 407 550 A1 is characterized in that itis composed of alternatingly disposed separation segments and wordsegments whereby the word portion consists of a certain number of bitlengths and the sequence of binary values of the separation segmentsmust not occur within this word length in order to permit cleardetection of the word segments.

This security element has the disadvantage, however, that there is nopossibility of fast visual checking as is necessary in many situationsof daily life.

It has therefore likewise been proposed to combine machine-testablesecurity features with visual features. EP 0 516 790 A1 discloses asecurity document with such a security element. The security threaddescribed here consists of a transparent plastic carrier layer with ametallic coating in which gaps are provided in the form of characters orpatterns, the so-called negative writing. If the thread is present inthe paper pulp, these gaps and the metallic surroundings are hardlyvisible when viewed by reflected light. When viewed by transmittedlight, however, the transparent gaps stand out in strong contrast fromtheir opaque surroundings and are thus easily recognized. At the sametime the security element has a magnetic coating which can e.g bedisposed congruently below the metal layer so that the gaps are presentcongruently in both layers. In this case a transparent plastic foil isfirst printed in the area of the later gaps with an activable inkcontaining foamable additives for example. Subsequently the plastic foilis provided in consecutive working steps first with a first metal layer,a magnetic layer and a second metal layer. Subsequent activation of theink, e.g. thermal action, causes the layers to be removed in the area ofthe activable ink so that the gaps arise.

Alternatively the magnetic coating can be provided below the metal layeronly in the edge areas of the thread and along the running direction ofthe element in the document, the gaps being disposed in the metal layerin the intermediate areas free from the magnetic layer. The transparentcarrier foil of the thread is printed in the edge areas with magneticmaterial in the form of strips. In the intermediate areas free from themagnetic layer the activable ink is applied in the form of the latergaps and the carrier foil then coated all over with the metal layer. Thefollowing activation of the ink finally gives rise to the gaps in themetal layer.

The invention is based on the problem of proposing a security documentwith a security element which allows not only a visual check but alsomachine testing and offers increased protection from forgery.

SUMMARY OF THE INVENTION

Hitherto it was impossible to combine a visual feature testable intransmission, such as the negative writing, with a magnetic codingusually consisting of spaced, opaque, magnetic areas. If the coding andthe negative writing are provided on the security element independentlyof each other, there is a danger of the opaque areas of the codingextending into the negative characters or even covering them completelyso that the characters are hardly or not at all recognizable intransmission. On the other hand, if one also provides the gaps in themagnetic layer in the overlap areas between magnetic layer and negativecharacters one can no longer distinguish without doubt between theactual coding and the superimposed characters when reading the coding.

The invention is based on the finding that the extension of the negativecharacters is in the micron range i.e., 1 to 999 microns and therefore asuitable choice of the extension of the magnetic areas and of thematerial parameters of the magnetic substance influencing the magneticflux will prevent the readability of the coding from being impaired bythe superimposed negative characters.

According to the invention a discontinuous magnetic layer in the form ofa coding is therefore provided below the opaque layer surrounding thenegative characters, the gaps also being present in the magnetic layerin the areas where the negative character gaps and the magnetic layeroverlap.

According to a preferred embodiment the security document has a securityelement with a translucent or transparent plastic layer on which amagnetic binary coding with a bit length of at least 2 to 4 mm and anopaque metal layer with negative characters are disposed, the metallayer being provided over the coding. In the areas where the negativecharacters overlap the magnetic layer the magnetic layer also has gapsin the form of the characters. Under the magnetic layer one can likewisedispose, for additional visual protection of the coding, a metal layer,e.g. of aluminum or metallic ink, which likewise has the negativecharacter gaps. The magnetic material and quantitative parameters areselected such that the magnetic flux is roughly twice as high as wouldbe necessary for reading the coding on an uninterrupted thread.

The inventive security element is produced in principle in two steps, inone case producing the magnetic coding and in the other case producingthe negative writing. In the following the various possibilities forproducing a magnetic coding and visually recognizable negative writingwill therefore first be explained independently of each other.

Since a magnetic layer is preferably covered by an essentially opaqueprotective layer on both sides for protection from forgery, the methodvariants described in the following include not only the production ofthe magnetic coding itself but also the possibilities for producing amagnetic coding with a subjacent cover layer. This is preferably ametallic layer which can be produced by any method, such as vacuummetalization, printing with bronze inks or the like. However otherlayers are of course also conceivable, such as a white color layer. Onecan also use color layers containing iridescent or liquid-crystalpigments or other optically variable effect layers, such as holograms.Semitransparent layers such as a semitransparent metal layer arelikewise conceivable.

Production Variant M1 (for Producing a Magnetic Coding)

The inverse of the desired magnetic coding is printed or a carrier foilwith an activable ink as a separation layer. Subsequently the lowercover layer and the magnetic layer are applied all over and uniformlydistributed. The separation layer is then activated, e.g. by treatmentwith a suitable solvent. The dissolving process can possibly besupported by surfactants, ultrasound or mechanical brushing. This causesthe separation layer and the superjacent layers to be removed. Themagnetic coding remains on the foil.

Production Variant M2 (for Producing a Magnetic Coding)

A continuous lower cover layer is first applied to a carrier foil. Theinverse of the magnetic coding is printed thereon with an activable inkas a separation layer. Subsequently the magnetic layer is applied allover and uniformly distributed. In the next operation the separationlayer is activated, for example likewise by treatment with a suitablesolvent. This process can possibly be supported by surfactants,ultrasound or mechanical brushing. In this way the layers are removed inthe area of the separation layer and the magnetic coding remains.However, the lower cover layer is present all over.

Production Variant M3 (for Producing a Magnetic Coding)

The magnetic layer is printed in the desired coding directly on acarrier foil or transferred in the desired coding thereto using atransfer method. The carrier foil can optionally have a cover layer.

Production variant M4 (for Producing a Magnetic Coding)

The magnetic layer is applied all over to a carrier foil alreadyprovided all over with the lower cover layer. Subsequently the patternof the coding is printed with a strongly adhesive ink. In a further stepthe magnetic layer is detached in the unprinted areas, possiblysupported by ultrasound or mechanical brushing. The protective andstrongly adhesive ink layer can optionally be detached subsequently.

Production Variant M5 (for Producing a Magnetic Coding)

The magnetic layer is applied all over to a carrier layer alreadyprovided with the lower cover layer. Subsequently the inverse of themagnetic coding is printed with a caustic ink containing e.g. an acid,solvent or complexing agent. This causes the unwanted parts of themagnetic layer to be detached and the magnetic coding to remain. Thedetaching process can again be supported by surfactants, ultrasound ormechanical brushing.

The opaque or at least partly opaque layer having the negativecharacters can, like the abovementioned first cover layer, consist of ametal layer, an opaque ink, a bronze ink, a hologram or the like. Theterm “opaque layer” used in the following also includes essentiallyopaque layers, such as semitransparent metal layers or inks withoptically variable pigments such as interference layer pigments orliquid-crystal pigments. For producing the light, visually easilyrecognized characters against an opaque background one can fundamentallyuse the following possible methods.

Production Variant V1 (for Producing Gaps)

A translucent carrier foil is printed in the form of the latercharacters using a soluble ink as a separation layer. This layerstructure is subsequently provided with the opaque layer. Then theseparation layer is detached with a suitable solvent, which leads todetachment of the superjacent layer.

Production Variant V2 (for Producing Gaps)

A carrier foil is provided with at least one opaque layer by printing orvaporization. Then a strongly adhesive, translucent ink is printed onthe uppermost cover layer in the form of the inverse of the later gaps,and the non-covered areas subsequently removed by being etched off ordissolved.

Production Variant V3 (for Producing Gaps)

A carrier foil is printed with a n opaque ink containing for examplebronze powders, white titanium dioxide pigments or optically variablepigments, the negative characters being left out.

Production Variant V4 (for Producing Gaps)

A carrier foil is printed or vaporized with at least one opaque layer.Then a caustic ink containing for example an acid, solvent or complexingagent is applied to the sequence of layers in the form of the later gapsso that the subjacent layers are removed except for the carrier foil.

These separately specified methods for producing a magnetic coding andnegative writing can be combined at will in order to obtain an inventivesecurity element or security document. A carrier foil, preferably inendless form, is provided both with the magnetic coding and with thesuperjacent negative writing. Subsequently this carrier foil is cut intosecurity elements with the desired form, preferably strips or bands. Ina last step this security element is connected with the securitydocument material. The element can be for example embedded in thedocument material as a security thread or fastened all over to thedocument surface. The carrier, oil can also act merely as anintermediate carrier, i.e. the layer structure consisting of negativewriting and magnetic coding is transferred to the document by means ofan adhesive or lacquer and the carrier foil then removed. In this caseone must sure the order is right when producing the layers on theintermediate carrier so that the magnetic coding comes to lie under thenegative writing on the document.

DESCRIPTION OF THE DRAWINGS

Further embodiments of the subject matter of the invention and theiradvantages will be explained more closely with reference to thefollowing figures, in which:

FIG. 1 shows a security document according to the invention,

FIG. 2 shows a basic layer structure of the inventive security element,

FIGS. 3 to 18 show method variants for producing the inventive securityelement.

DETAILED DESCRIPTION

FIG. 1 shows an inventive security document, here a bank note, in whichsecurity element 2 is embedded in the form of a so-called windowsecurity thread. The security thread is quasi woven into the paper pulpduring papermaking so that it passes directly to the document surface atregular intervals, which is indicated by the hatched boxes.Alternatively it is also possible, however, to embed the threadcompletely in the paper or to connect it with the document material suchthat it can be been all over on the surface. Also, security element 2need of course not necessarily be incorporated in the form of a strip orband. In particular if the security element is applied all over to thesurface of the security document, other outline forms such as a circularmark can also be advantageous.

FIG. 2 shows the basic layer structure of inventive security element 2.It consists of carrier foil 3, which can optionally be lacking if theelement is fastened to the document surface. On carrier foil 3 there arefirst opaque cover layer 4, magnetic layer 5, second cover layer 6 andoptionally transparent protective layer 7. First opaque cover layer 4and magnetic layer 5 are present on carrier foil 3 only in partial areasand separated from each other by intermediate areas 8. The magneticareas form any desired coding by their arrangement.

According to a preferred embodiment the carrier foil can be divided intosegments of equal length A, each segment corresponding to a binary bit.The coating of bit length A with magnetic material can correspond forexample to a “1” and the uncoated segment of same length A to a “0”. Inthe shown representation, intermediate areas 8 and magnetic areas 5therefore constitute integral multiples of length A. One of intermediateareas 8 for example has length A while the other has a length of 2 Acorresponding to the bit sequence “00”. The same applies to magneticareas 5 shown.

Magnetic areas 5 and lower cover layer 4 additionally have gaps 9 in theform of characters, patterns, etc. Gaps 9 constitute negative charactersreadable in transmission. Extension B of these characters is in themicron range preferably in the range of hundreds of microns and thus anorder of magnitude below minimum distance A between two magnetic areas5, which is preferably between 2 to 4 mm.

Cover layer 6 disposed over magnetic areas 5 extends over total securityelement 2 and has only gaps 9 of the negative characters. Cover layers4, 6 can consist of any opaque materials, but are preferably vaporizedmetal layers such as aluminum layers or optically variable layers suchas holograms or printing inks with effect pigments (e.g. interferencelayer pigments, liquid-crystal pigments, bronze powders).

Depending on the production method it is also possible to provide lowercover layer 4 also in the area of code segments 8 free from the magneticlayer.

FIGS. 3 to 18 illustrate the various production methods for an inventivesecurity element. These are different combinations of methods M1 to M5and V1 to V4 described above.

Combination of Methods M1 and V1

FIG. 3 shows the various method steps necessary for obtaining theinventive security element combining method variants M1 and V1 describedabove. Carrier foil 3 is printed in step a) with a first separationlayer, e.g. a water-soluble ink, in the form of the visuallyrecognizable negative characters. In second method step b) abenzine-soluble ink corresponding to the inverse pattern of the magneticcoding is printed in partial overlap with this water-soluble ink. Instep c) lower cover layer 4 and magnetic layer 5 are then applied allover and homogeneously to printed carrier foil 3. This can be done bymerely applying a coating compound or by vaporizing. In step d) ink 11is then dissolved using the suitable solvent, e.g. benzine, therebywashing out superjacent layers 4 and 5. This gives rise to codingsegments 8 free from the magnetic layer. Since ink 10 is not soluble inthe solvent of ink 11 these printed areas remain unchanged. In furtherstep e) this layer structure is provided with further all-over opaquelayer 6. In step f) gaps 9 in the form of the negative characters areproduced by treatment with a suitable solvent for ink 10. Finally, inlast step g) the finished layer structure of the element can be coveredwith additional protective layer 7.

Combination of Methods M2 and V1

FIG. 4 shows the production variant according to a combination ofmethods M2 and V1. Carrier foil 3 is printed with ink 10 in the form ofthe later negative characters (step a)) and then provided all over withfirst cover layer 4 (step b)). Over cover layer 4 activable ink 11 isapplied in the form of the inverse magnetic coding. Inks 10 and 11 arelike-wise selected so as to be soluble in different solvents. In thesubsequent step this layer structure is provided with magnetic layer 5(step d)) and ink 11 then activated so that coding segments 8 free fromthe magnetic layer arise (step e)). In step f) the all-over coating withsecond cover layer 6 is performed and then the activation of ink 10(step g)) for producing negative characters 9. Finally protective layer7 can be applied in step h).

Combination of Methods M3 and V1

FIG. 5 shows a production variant according to a combination of methodsM3 and V1. In step a) carrier foil 3 is printed with first separationlayer 10 and then coated all over with first cover layer 4 (step b)).Finally magnetic layer 5 is printed or transferred by the transfermethod in the form of the desired magnetic coding, whereby intermediateareas 8 remain free from the coating (step c)). In step d) the coatingwith second cover layer 6 is performed. In subsequent step e) ink 10 isactivated so that the superjacent sequence of layers is removed andreadable negative characters 9 remain (step e)). Finally the element canbe coated with additional protective layer 7 (step f)).

Combination of Methods M4 and V1

FIG. 6 shows the production variant according to a combination ofmethods M4 and V1. Here too carrier foil 3 is printed in first step a)with soluble ink 10 in the form of the later negative characters. Thenfirst cover layer 4 is first provided all over on the printed side ofthe carrier foil (step b)) and magnetic layer 5 likewise applied allover (step c)). In subsequent step d) the magnetic layer is printed withstrongly adhesive ink 12 in the form of the coding. Layer 12 isresistant to solvents of magnetic layer 5 so that in subsequentdissolving process e) only the unprinted areas are detached, giving riseto coding segments 8 free from the magnetic layer. In step f) thecoating with second cover layer 6 is finally performed. The followingactivation of ink 10 in step g) gives rise to gaps 9 in the form of thenegative characters in the total layer structure. In optional step h)the inventive layer structure can finally be provided with furtherprotective layer 7.

Combination of Methods M5 and V1

FIG. 7 shows a production variant according to the combination ofmethods M5 and V1. Here too carrier foil 3 is printed in a first stepwith soluble ink 10 in the form of the later negative characters (stepa)) and then provided with first cover layer 4 and magnetic layer 5(steps b) and c)). Finally magnetic layer 5 is printed with caustic ink13 in the form of the inverse magnetic coding (step d)) so that in thisarea the magnetic layer is removed and coding areas 8 free from themagnetic layer arise (step e)). Then the coating with second cover layer6 is performed again (step f)) ink 10 activated to produce negativecharacters 9 (step g)), and further protective layer 7 optionallyprovided (step h)).

Combination of Methods M1 and V2

FIG. 8 shows the production variant according to a combination ofmethods M1 and V2. Carrier foil 3 is printed in first step a) withactivable ink 11 in the form of the inverse magnetic coding and then instep b) coated or vaporized all over with first cover layer 4 andmagnetic layer S. In subsequent step c) ink 11 is activated so thatcoding segments 8 free from the magnetic layer arise. In step d) thecoating with second cover layer 6 is performed, All-over cover layer 6is printed in step e) with strongly adhesive and solvent-resistant ink14 in the form of the inverse later negative characters. Then the layerstructure is subjected to a dissolving process (step f)) in which theareas not covered by ink 14 are dissolved except for the carrier foil,giving rise to negative characters 9. The layer structure can again beprovided in optional step g) with further protective layer 7.

Combination of Methods M2 and V2

FIG. 9 shows the production variant according to a combination ofmethods M2 and V2. In this case carrier foil 3 is first provided allover with lower cover layer 4 (step a)). The inverse of the magneticcoding is printed thereon with activable ink 11 (step b)). In step c)magnetic layer 5 is finally provided on the layer structure uniformlyand all over. In subsequent step d) ink 11 is activated, therebyremoving magnetic layer 5 in the area of ink 11 so that coding segments8 free from the magnetic layer arise. In subsequent step e) second coverlayer 6 is provided all over on the layer structure, and then printed instep f) with strongly adhesive and solvent-resistant ink 14 in the formof the inverse later negative characters. In next step g) the layerstructure is treated with a solvent which detaches both cover layers 4and 6 and magnetic layer 5 from carrier foil 3 in the areas which arenot covered by solvent-resistant layer 14 (step g)). In this waynegative characters 9 are produced. Finally the total layer structurecan be provided in optional step h) with protective layer 7.

Combination of Methods M3 and V2

FIG. 10 shows the production variant according to a combination ofmethods M3 and V2. In this case carrier foil 3 is provided with firstcover layer 4 (step a)), as described in the preceding productionvariants. In step b) the magnetic coding is produced directly byprinting an ink containing magnetic pigments. In steps c) to e) one thenproduces negative characters 9 by first providing second cover layer 6over magnetic coding 5, then printing it with solvent-resistant ink 14in the form of the inverse negative characters and finally treating thelayer structure with a solvent in order to produce negative characters9. Finally the total layer structure can be provided with protectivelayer 7, as in all the other variants.

Combination of Methods M4 and V2

FIG. 11 shows the production variant according to a combination ofmethods M4 and V2. In steps a) and b) carrier foil 3 is provided allover with first cover layer 4 and magnetic layer 5. Subsequently theinverse of the magnetic coding is applied with strongly adhesive,solvent-resistant ink 12. In step d) the layer structure is finallytreated with a solvent which detaches only magnetic layer 5 and notcover layer 41 so that coding segments 8 free from the magnetic layerarise above first cover layer 4. In the next step the layer structure islikewise provided all over with second cover layer 6 (step e)) and thenprinted with solvent-resistant ink 14 in the form of the inversenegative characters (step f)). In step g) one produces negativecharacters 9, as described above, by detaching layers 4, 5, 12, 6 in theareas where ink 14 is not present. In step h) protective layer 7 canfinally be provided as a covering again.

Combination of Methods M5 and V2

FIG. 12 shows the production variant according to a combination ofmethods M5 and V2. The carrier foil is likewise provided all over withfirst cover layer 4 and magnetic layer 5 (steps a) and b)). Then in stepc) the inverse of the magnetic coding, i.e. the area of the later areasfree from the magnetic layer, is printed with a caustic ink containingan acid or suitable solvent. The caustic or solvent ink removes onlymagnetic layer 5 so that coding segments 8 free from the magnetic layerarise. Then, as described in the above examples, the layer structure iscovered all over with second cover layer 6 (step e)), asolvent-resistant ink is printed in the form of the inverse of thenegative characters (step f)), and the layer structure is then detachedin the unprinted areas to produce negative characters 9 (step g)).Finally protective layer 7 can be provided again (step h)).

Combination of Methods M1 and V3

FIG. 13 shows the production variant according to a combination ofmethods M1 and V3. In this case both the inverse of the desired magneticcoding and the negative characters are printed on carrier foil 3 withsoluble ink 11 as a separation layer. In step b) first cover layer 4 andmagnetic layer F are disposed all over ink 11. In subsequent step c) ink11 is activated so that negative characters 9 and coding segments 8 freefrom the magnetic layer arise. In step d) the layer structure is finallyprinted in good register with second cover layer 6, whereby negativecharacters 9 are left out. Finally protective layer 7 can be applied instep e).

The production variants according to a combination of methods M2 to M5and V3 will not be presented in the following with reference to figuressince they virtually do not differ from the production of the magneticcoding in the sequence of method steps. In these variants one mustmerely also produce gaps for the negative characters in the magneticlayer simultaneously with the magnetic coding. The last step isfundamentally to print the second cover layer which is left out in thearea of the negative characters.

Combination of Methods M1 and V4

FIG. 14 shows the production variant according to a combination ofmethods M1 and V4. Carrier foil 3 is printed in first step a) withactivable ink 11 in the form of the inverse magnetic coding and then instep b) coated or vaporized all over with first cover layer 4 andmagnetic layer 5. In subsequent step c) ink 11 is activated so thatcoding segments 8 free from the magnetic layer arise. Then the coatingwith second cover layer 6 is performed (step d)). A caustic inkcontaining for example an acid, solvent or complexing agent is appliedto cover layer 6 in the form of the later negative characters. Causticink 15 must be selected so that it can remove both cover layers 4 and 6and magnetic layer 5. This gives rise to negative characters 9 (stepf)). In last step g) the layer structure can finally be provided withprotective layer 7 again.

Combination of Methods M2 and V4

FIG. 15 shows the production variant according to a combination ofmethods M2 and V4. Carrier foil 3 is provided in steps a) to e) with themagnetic coding and second cover layer 6 by providing on carrier foil 3first cover layer 4 (step a)), soluble layer 11 in the form of theinverse magnetic coding (step b)) and all-over magnetic layer 5 (stepc)). Then ink 11 is activated so that coding segments 8 free from themagnetic layer arise (step d)). Finally second cover layer 6 is appliedto the layer structure (step e)). In subsequent step f) cover layer 6 isprinted with caustic ink 15 in the form of the later negativecharacters. Ink 15 dissolves layers 4, 5 and 6 so that gaps arise in thelayer structure, negative characters 9 (step g)). Optionally protectivelayer 7 can finally be provided (step h)).

Combination of Methods M3 and V4

FIG. 16 shows the production variant according to a combination ofmethods M3 and V4. In accordance with method M3 carrier foil 3 is firstprinted with first cover layer 4 and then with magnetic coding 5 (stepsa) and b)). Subsequently second cover layer 6 is applied (step c)). Asdescribed above, the treatment with caustic ink 15 in the form of thelater gaps is now performed, giving rise to negative characters 9 (stepsd) and e)). Finally protective layer 7 can be provided in step f) again.

Combination of Methods M4 and V4

FIG. 17 shows the production variant according to a combination ofmethods M4 and V4. Carrier foil 3 already provided all over with lowercover layer 4 (step a)) has magnetic layer 5 applied thereto all over(step b)). Subsequently the pattern of the magnetic coding is printedwith insoluble ink 12 (step c)). In step d) magnetic layer 5 is detachedin the unprinted areas. In next step e) second cover layer 6 is applied,and in steps f) and g) the treatment with caustic ink 15 is performed,giving rise to negative characters 9. Finally the layer structure can becovered with protective layer 7 (step h)).

Combination of Methods M5 and V4

FIG. 18 shows the production variant according to a combination ofmethods M5 and V4. In this method, as described repeatedly above,carrier foil 3 is first coated or vaporized all over with cover layer 4and then with magnetic layer 5 (steps a) and b)). Then the layerstructure is treated with caustic ink 13 which detaches the unwantedparts of magnetic layer 5 thereby producing coding segments 8 free fromthe magnetic layer (steps c) and d)). Subsequently one produces thenegative characters in the total layer structure by first applying coverlayer 6 (step e)) and subsequently performing the treatment with furthercaustic ink 15 which produces the gaps or negative characters 9 (stepsf) and g)). Finally the layer structure can be provided with protectivelayer 7 (step h)).

The untreated surface of the carrier foil can of course be provided inall method variants with further layers, such as all-over,semitransparent metal layers or luminescent prints.

The various method steps are preferably performed in a continuous methodon a plastic foil in web form. Then the finished foil is cut intosecurity elements of the desired form and these are connected with thedocument material. The element can be embedded in the document materialduring production of the document, e.g. as a window security thread. Ifthe element is to be disposed on the document surface the element isconnected with the document material via a suitable adhesive layer,whereby the carrier foil preferably comes to lie on the side facing awayfrom the document as a protective layer.

Alternatively the endless carrier material can also be used as atransfer foil. In this case the carrier foil must be prepared such thatthe layer structure can be detached therefrom, e.g. by providing aspecial separation layer.

What is claimed is:
 1. A security document (1) comprising a documentsubstrate and a security element (2), said security element (2) havingat least a first layer (6) with first gaps (9) which form negativecharacters readable upon transmission of light through said document anda magnetic layer (5) disposed below said first layer (6), said firstlayer superposed on said magnetic layer, said magnetic layer (5) havingsecond gaps (8) in the form of a magnetic coding and said first gaps (9)of said first layer (6) extending through said magnetic layer (5) whereno second gaps (8) are located in said magnetic layer (5), wherein saidfirst gaps (9) of said first layer (6) are an order of magnitude smallerthan said second gaps (8) of said magnetic layer (5) such thatreadability of said coding in said magnetic layer (5) is not impaired inareas where said first gaps (9) extend through said magnetic layer (5).2. The security document of claim 1, including a further layer (4)underlying the magnetic layer (5) with the first gaps (9) extending alsothrough said further layer (4).
 3. The security document of claim 1,wherein the first layer (6) is selected from the group consisting of ametallic layer, a hologram and a printing ink.
 4. The security documentof claim 1, wherein the first gaps (9) are present in the form ofcharacters.
 5. The security document of claim 1, wherein the first gaps(9) are present in the form of patterns.
 6. The security document ofclaim 1, wherein said second gaps are of various sizes including aminimum size, and wherein the first gaps (9) have a size that is anorder of magnitude below a minimum size of said second gap (8).
 7. Thesecurity document of claim 1, wherein the minimum size of said secondgaps (8) is preferably between 2 to 4 mm.